Three dimensional spatial separation of cells in response to microtopography

Biomaterials ◽  
2013 ◽  
Vol 34 (33) ◽  
pp. 8097-8104 ◽  
Author(s):  
Alexandre Leclerc ◽  
Dominique Tremblay ◽  
Sebastian Hadjiantoniou ◽  
Nickolay V. Bukoreshtliev ◽  
Jacob L. Rogowski ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Spatial Separation

scholarly journals ESTRUCTURA DE LA COMUNIDAD EPIFAUNAL ASOCIADA A COLONIAS DE VIDA LIBRE DEL HIDROCORAL MILLEPORA ALCICORNIS LINNAEUS 1758 EN BAHÍA PORTETE, CARIBE COLOMBIANO

2016 ◽  
Vol 35 ◽  
Author(s):  
Carolina Castro S. ◽  
Mario Monroy L. ◽  
Oscar David Solano
Keyword(s):  
Coral Species ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Juvenile Stage ◽  
Living Tissue ◽  
Free Living ◽  
Invertebrate Species ◽  
Epifaunal Community ◽  
Dimensional Growth ◽  
Petrolisthes Armatus

The epifaunal community associated with free-living colonies of Millepora alcicornis, the dominant coral species in Portete Bay, was characterized from twenty living colonies randomly collected within a shallow Thalassia testudinum seabed. The three-dimensional growth colonies sheltered 15 families, 15 genera and 18 mobile invertebrate species. The 97% of individuals was represented by decapods crustaceans specially adapted as to live in association with the host. Within them, the porcelanid Petrolisthes armatus, representing 79% of the epifauna (961 individuals), was exclusively found in a juvenile stage suggesting that M. alcicornis is mainly used by this species as a nursery zone. The epifaunal composition is partially related to coral living tissue whereas the principal simbionts size is correlated with the spatial separation of coral branches. In spite of being slightly diverse in comparison with the epifaunal community found in other coral species, the epifauna found in M. alcicornis is of great interest and peculiarity by their association with the free-living form of this coral.

scholarly journals A Spatial Filter Approach to Evaluating the Role of Convection on the Evolution of a Mesoscale Vortex

2013 ◽  
Vol 70 (7) ◽  
pp. 1954-1976 ◽  
Author(s):  
Glenn A. Creighton ◽  
Robert E. Hart ◽  
Philip Cunningham
Keyword(s):  
Three Dimensional ◽  
Spatial Separation ◽  
Spatial Filter ◽  
Tropical Cyclogenesis ◽  
Moist Convection ◽  
Mesoscale Vortex ◽  
Convective Scale ◽  
Vortical Hot Towers ◽  
Order Of Magnitude ◽  
Deep Moist Convection

Abstract A new spatial filter is proposed that exploits a spectral gap in power between the convective scale and the system (“vortex”) scale during tropical cyclone (TC) genesis simulations. Using this spatial separation, this study analyzes idealized three-dimensional numerical simulations of deep moist convection in the presence of a symmetric midlevel vortex to quantify and understand the energy cascade between the objectively defined convective scale and system scale during the early stages of tropical cyclogenesis. The simulations neglect surface momentum, heat, and moisture fluxes to focus on generation and enhancement of vorticity within the interior to more completely close off the energy budget and to be consistent for comparison with prior benchmark studies of modeled TC genesis. The primary contribution to system-scale intensification comes from the convergence of convective-scale vorticity that is supplied by vortical hot towers (VHTs). They contribute more than the convergence of system-scale vorticity to the spinup of vorticity in these simulations by an order of magnitude. Analysis of the change of circulation with time shows an initial strengthening of the surface vortex, closely followed by a growth of the mid- to upper-level circulation. This evolution precludes any possibility of a stratiform precipitation–induced top-down mechanism as the primary contributor to system-scale spinup in this simulation. Instead, an upscale cascade of rotational kinetic energy during vortex mergers is responsible for spinup of the simulated mesoscale vortex. The spatial filter employed herein offers an alternative approach to the traditional symmetry–asymmetry paradigm, acknowledges the highly asymmetric evolution of the system-scale vortex itself, and may prove useful to future studies on TC genesis.

The Effect of Two-Dimensional and Three-Dimensional Distance on Apparent Motion

Perception ◽  
1983 ◽  
Vol 12 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Kathleen Mutch ◽  
Isabel M Smith ◽  
Albert Yonas
Keyword(s):  
Motion Perception ◽  
Apparent Motion ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Three Dimensions ◽  
Correspondence Problem ◽  
Two Dimensional ◽  
Motion Display ◽  
Specific Concern ◽  
Actual Depth

The problem of how the visual system matches corresponding inputs from one instant to the next to produce the perception of motion has been experimentally examined. The specific concern was whether this correspondence problem is solved prior to the interpretation of three-dimensional distance. Observers judged the degree of apparent motion between pairs of lights in a conflicting motion display. Spatial separation of the lights was varied in two and three dimensions in order to assess whether retinal distance, actual depth, or some combination of these provided critical information for correspondence. The results support Ullman's contention that only two-dimensional (retinal) distances are used in establishing correspondence in motion perception.

scholarly journals Computation of multi-region, relaxed magnetohydrodynamic equilibria with prescribed toroidal current profile

2021 ◽  
Vol 87 (4) ◽  
Author(s):  
A. Baillod ◽  
J. Loizu ◽  
Z.S. Qu ◽  
A. Kumar ◽  
J.P. Graves
Keyword(s):  
Three Dimensional ◽  
Spatial Separation ◽  
Force Balance ◽  
Current Profile ◽  
Pressure Equilibrium ◽  
Pressure Driven

The stepped-pressure equilibrium code (SPEC) (Hudson et al., Phys. Plasmas, vol. 19, issue 11, 2012, 112502) is extended to allow the computation of multi-region, relaxed magnetohydrodynamics (MRxMHD) equilibria at prescribed toroidal current profile. Toroidal currents are expressed in the framework of the MRxMHD theory, exhibiting spatial separation between pressure driven and externally driven currents. Additionally, analytical force balance derivatives at constant toroidal current are deployed in order to maintain SPEC's advantageous speed. The newly implemented capability is verified in screw pinch and classical stellarator geometries, and is applied to obtain the equilibrium $\beta$ -limit of a classical stellarator without net toroidal currents. This new capability opens the possibility to study the effect of toroidal current on three-dimensional equilibria with the SPEC code.

Masking between Spatially Separated Sounds

1992 ◽  
Vol 36 (3) ◽  
pp. 253-257
Author(s):  
Michael D. Good ◽  
Robert H. Gilkey
Keyword(s):  
Free Field ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Spatial Separation ◽  
Median Plane ◽  
Sound Sources ◽  
Auditory Displays ◽  
Spectral Cues ◽  
Masking Release ◽  
Release From Masking

The development of optimal three-dimensional auditory displays requires a more complete understanding of the interactions among spatially separated sounds. Free-field masking was investigated as a function of the spatial separation between signal and masker sounds within the horizontal, frontal, and median planes. The detectability of filtered pulse trains in the presence of noise maskers was measured using a cued, two-alternative, forced-choice, adaptive staircase procedure. Signal and masker combinations in low (below 2.3 kHz), middle (1.0–8.5 kHz), and high (above 3.5 kHz) frequency regions were examined. As the sound sources were separated within the horizontal plane, signal detectability increased dramatically. Similar improvement in detectability was observed within the frontal plane. As suggested by traditional binaural models, interaural time cues and interaural intensity cues are likely to play a major role in mediating masking release in both the horizontal and frontal planes. Because no interaural cues exist for stimuli presented within the median plane, traditional models would not predict a release from masking when the stimuli are separated within this plane. However, with high frequency signals, masking release similar to that observed in the horizontal and frontal planes could be observed in the median plane. The current literature suggests that sound localization in the median plane may depend on direction-specific spectral cues that are introduced by the pinna at high frequencies. The masking release observed here may also depend on these “pinna cues.”

scholarly journals Critical point for Bose–Einstein condensation of excitons in graphite

2020 ◽  
Vol 117 (48) ◽  
pp. 30215-30219
Author(s):  
Jinhua Wang ◽  
Pan Nie ◽  
Xiaokang Li ◽  
Huakun Zuo ◽  
Benoît Fauqué ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Critical Magnetic Field ◽  
Quantum Limit ◽  
Einstein Condensation ◽  
Collective State ◽  
Bose Einstein Condensation ◽  
Electron Hole Pair ◽  
Bose Einstein

An exciton is an electron–hole pair bound by attractive Coulomb interaction. Short-lived excitons have been detected by a variety of experimental probes in numerous contexts. An excitonic insulator, a collective state of such excitons, has been more elusive. Here, thanks to Nernst measurements in pulsed magnetic fields, we show that in graphite there is a critical temperature (T = 9.2 K) and a critical magnetic field (B = 47 T) for Bose–Einstein condensation of excitons. At this critical field, hole and electron Landau subbands simultaneously cross the Fermi level and allow exciton formation. By quantifying the effective mass and the spatial separation of the excitons in the basal plane, we show that the degeneracy temperature of the excitonic fluid corresponds to this critical temperature. This identification would explain why the field-induced transition observed in graphite is not a universal feature of three-dimensional electron systems pushed beyond the quantum limit.

Modeling Corrosion of a Metal under an Aerosol Droplet

2010 ◽  
Vol 654-656 ◽  
pp. 1650-1653 ◽  
Author(s):  
Murali Sankar Venkatraman ◽  
Ivan S. Cole ◽  
Dayalan R. Gunasegaram ◽  
Bosco Emmanuel
Keyword(s):  
Metal Surface ◽  
Atmospheric Corrosion ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Temporal Variations ◽  
Transient Model ◽  
Aerosol Droplet ◽  
Current Densities ◽  
Spatio Temporal ◽  
Kinetics Of

On a metal surface covered with a moisture layer of variable thickness and shape, the dissolved oxygen may induce a spatial separation of the anodic and cathodic reactions on space-time scales characteristic of the roughness, droplet size and the local kinetics of the system. This leads to a spatio-temporal variations in species concentrations, current and potential over the metal surface and thus atmospheric corrosion. Here a fully three-dimensional transient model is developed that addresses the corrosion of a metal under an aerosol droplet. The effects of various parameters, such as exchange current densities, initial concentrations, shape and size of the droplet, and diffusivity of oxygen on ionic, potential and current distributions are investigated.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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